1. Field of the Invention
The present invention relates to a method for monitoring the condition of rail switch points and for detecting premature abrasive wear-and-tear in the region of the tongue switching rail of the rail switch points.
2. Description of the Related Art
A positioning, safety and monitoring device has already become known from the German Patent DE 364891A1, wherein a plurality of point drives, having an internal closure, driven by electric motors are employed. By a series of sensors, in these known devices, the currently-involved end position of the slide member, and its safety position, are monitored. A series of such units are combined in functional zones and in all cases are controlled and monitored in common. In particular, details of a monitoring device for the end positions of swivelling rails of rail switch points may be gleaned from DE 2630387B2, wherein switches are provided for both end positions of each swivelling rail. In this case, an evaluation device for signalling a correct end position includes the involvement of all the switches of every rail for one end position and the simultaneous non-involvement of all the switches for the corresponding other end position.
In the known utilization of sensors on rail switch points, the final setting position is monitored in each case, in order to ensure safety when said switch points are travelled upon. However, safe travelling over a switch point is still possible if an end position is maintained within a pre-determined tolerance. Within the range of this pre-determined tolerance, it is true that abrasion phenomena in the region of contact with the running wheels can bring about measurable changes which, in the case of known devices, cannot be detected. An excessive amount of abrasive wear-and-tear in the region of rail switch points is only detected by the known devices when the safety of the points could no longer be relied upon. When this occurs, the maintenance work is substantially more involved and expensive, resulting in essentially longer periods of non-use.